Structure of the Atom — Science STD 9 — Question

A non-metal has 6 electrons in its outermost shell. Predict its valency.

Which one amongst the following will show Tyndall effect?
Copper sulphate solution.

‘A substance has a definite shape as well as a definite volume’. Which physical state is represented by this statement?

Give the names of the elements present in the following compounds.

Baking powder.

Name the scientist who gave:
Law of constant proportions.

Name the technique to separate butter from curd.

How is the size of an atom indicated?

State whether the following statements are true or false:
Salt and water can be recovered from an aqueous salt solution by the process of evaporation.

Calculate the molecular mass of nitric acid, HNO₃.
(Atomic masses: H = 1u; N = 14u; O = 16u)

A piece of chalk can be broken into small particles by hammering but a piece of iron cannot be broken into small particles by hammering. Which characteristic of the particles of matter is illustrated by these observations?